Recovery of valuable hydrocarbons



Patented se ta, 1944 7 UNITED STATES. [PATENT OFFICE V RECOVERY OF VALUABLE HYDROCARBON S Frederick W. Breuer, Haverford, Pa., assignor to The United Gas Improvement Company, a corporation of Pennsylvania No Drawing. Application .Iuly 12, 1940,

. Serial No. 345,101

6 Claims. (Cl. .2606 81'.5)'

This invention relates to improvements in the preparation of C diolefins in practicallypure form by'combination with solid dry heavy metal salts, of groups I and 2 of the periodic system. The prior art on the separation of diolefins by means of cuprous salts has dealt'wlth solutions of cuprous salts and cuprous salt complexes in aqueous and non-aqueous media. esses are subject to serious difliculties both because of the relative instability of thesetypes of absorbents as well as because oftheir corrosive action upon reactors made (if iron or other commonly used construction metals. Furthermore, the separation of diolefins from the oleflns in mixtures such as formed in cracking operations by means of cuprous salts and, their complexes when dissolved in aqueous or non-aqueous media is incomplete, because these systems are known to dissolve or absorb considerable amounts of monoolefins more or less firmly Modifications of the separation process of dioleflns applying soluble cuprous complexes'have necessitated the use of large excesses of solu bilizing agents, such as chlorides oi the alkali and alkaline earth metals or amine salt thereby decreasing the efliciency of the process and the utilization of the cuprous chloride, because an equilibrium according to-the following equation:

R representing alkali or alkaline earth metal or an amine radicalis established. Although the deleterious action of excess RC1 can be eliminated to acertain extent by the addition of undissolved cuprous chloride, filtration and pump- These procand of monoolefins'free of diolefins is of great practical importance. a l

The mentioned absorbing substances are applied as finely divided powders orsuspended or precipitated on suitable; carriers, such as di-- atomaceous earth and other materials which under the conditions of operation do not act upon the C5 diolefins and accompanying bodies.

Example 1 {in a suitable reaction vessel 173.6 parts by weight of a liquid hydrocarbon cut, containing 65% by weight of piperylene areadded in portions to 600 parts by weight of dry powdered cuprous chloride, care being taken to dissipate the heat of reaction by means of suitably arranged eooling. After one" and one half hours of thorough mixing the unreacted hydrocarbons are boiled off and subsequently the piperylene cuprous chloride complex is decomposed by heatingto 65 C. with a finalreduction of pressure to 400' mm. Hg. An excellent yield of 100% piperylene-i's obtained. It is advisable to apply temperatures not higher than 110 p. in order to avoid secondary reactions.

Examples? 80 parts by weight of a fraction of cracked hydrocarbon material boiling essentially between ing problems in a continuous process are madci considerably more dimcult and costly.

It has now been found that separation of C5 diolefins from other substances can be efiected more economically and in a. higher degree of purity by solid salts in the absence of a liquid dissolving or suspending medium' Whereas e. g. the dissociation pressure of a diolefin cuprous chloride adduct is ofthe order J of a few millimeters mercury, the correspond- I ing dissociation pressures for ethylene, propylene Example 1.

' metals, alkaline earths, ammonia, and/or sub 1 mixed, deposited or precipitated on solid finely I and butylene additive compounds are about 3 atmospheres or higher. When working at atmosphericpressures monoolefins' are therefore not absorbed on dry solid cuprous chloride and 'a highly selectiveabsorption and separation of diolefins is effected. Vice versa, monoolefins free of diolefins are obtained. The manufacture of diolefins free of impurities such as monoolefins v tration and that changes, omissions, additions;

stituted amines, followed by liberation of the C5 diolefins from the resulting additive compounds. If desired the foregoing complexes may be divided substances of large surface area which under the conditions obtaining do not act upon C5 diolefins and/or accompanying substances.

Having particularly described my invention it is to be understood that this is by way of illus+ substitutions and/or modifications might be made within thev scope of the claims without departing from the spirit thereof.

lclaim: l. A process for the recovery of a C5 dioleflne material from a mixture thereof containing other hydrocarbons which comprises contacting said mixture in the liquid phase with a solid dry complex of a salt of a heavy metal oi groups I and II V 2. A process for the recovery at a C5 dioleilne material from a mixture thereoi containing other hydrocarbons which comprises contacting said mixture in the liquid phase with a solid dry complex oi cup'rouschlorlde with a salt selected irons the group consisting oi salts oi the amali metals, alkaline earth metals, ammonia and-substituted amines, and under conditions of temperature and pressure such that said complex lforms an addition compound with said Cs dlolerlne material to the substantial exclusion oi other than dioleflne components of the mixture, separating said addl tion compound from the remaining mixture, and

liberating said Co diclefine material i'rom said additlon compound with the aid or heat.

, 3. A process for the recovery oi isoprene from a mixture thereoi containing other hydrocarbons which comprises contacting said mixture in the liquid phase with a solid dry complex of a salt of a heavy metal oi groups I and Elliot the periodic system with a salt selected ircro'the group conaeeaoao 4. A process for the recovery of isoprene from a mixture thereof containing other hydrocarbons which comprises contacting said mixture in the liquid phase with a solid dry complex or cuprous chloride with a salt selected from the group consisting of! salts of alkali metals, alkaline earth metals, ammonia, and substituted amines, and

under conditions of temperature and pressure such that said complex forms an addition compound with said isoprene to the substantial exclusion of other than diolefine components of the mixture, separating said addition compound from the remaining mixture, and liberating said isoprene from said addition compound with the aid 01 heat,

5. A process for the recovery of piperylene from a mixture thereof containing other hydrocarbons which comprises contacting said mixture in the liquid phase with a solid dry complex of a salt of a heavy metal of groups I and II of the periodic system with a salt selected from the group consisting of salts of alkali metals, alkaline earth metals, ammonia, and substituted amines, and under conditions of temperature and pressure such that said complex forms an addition compound with said piperylene to the substantial ex; clusion oi other than dioleflne components of the mixture, separating said addition compound from sisting of salts of alkali metals, alkaline earth fmetals, ammonia, and substituted amines, and

under conditions oi temperature and pressure such that said complex iorihs an 'eddition'com pound "with said isoprerie to the substantial exclusion oi other than diolefine components oi the mixture, separating so addition compound from the remaining mixture, and liberating said iro prone trom said addition compound "with the oi heat,

the remaining mixture, and liberating said piperylene from said" addition compound with the aid or heat.

ii. A processfor the recovery of piperylene from Y a mixture thereof containing other hydrocarbons which comprises contacting said mixture in the liquid phase with a solid dry complex of cuprous chloride with a salt selected from the group consiating of salts of alkali metals, alkaline earth metals, ammonia, and substituted amines, and under conditions of temperature and pressure such that said complex forms an addition com pound with said piperylene to the substantial exclusion or other than dioleflne components or the mixture, separating said addition compound from the rem w mixture, and liberating said piper- ;vlene irom said addition compound with the aid oi heat.

FREDERICK W. BTBJLUIE'JFE.v 

